1. Field of the Invention
This invention relates in general to water softeners and in particular to a novel circuit for a water softener.
2. Description of the Prior Art
Probes to indicate resistance changes in ion exchange material in water softeners are shown in issued U.S. Pat. No. 3,373,351 to Stanley F. Rak and resistance sensing probe systems are disclosed in U.S. Pat. No. 3,159,573 to H. D. Ritchie. These systems of the prior art are designed to immediately rejuvenate and recondition the ion exchange resin which can occur at times when it is desirable that water be supplied from the system.
Thus, in the prior art various systems have been known for causing regeneration of the resin bed of a water softener such as manual regeneration, or regeneration based on a control device which initiates regeneration at fixed given intervals of time. The problem with these two systems is that the regeneration may occur before it is needed or, alternatively, it may not occur quickly enough and the water may not be properly softened toward the end of the interval. A third system for water softening is based on a control which causes water softening when the condition of the output water and/or the resin bed indicates that regeneration should occur. The problem with this type of system is that regeneration can occur at periods when there is a high demand for soft water and during regeneration generally the soft water is not available and the unsoftened is bypassed by the water softener.
Other known systems have utilized a pair of water softening or water conditioning apparatuses each having separate control units and in which the units are interconnected with interlocking devices to prevent both units from being in the regenerating condition at the same time and an example of this type of system is disclosed in U.S. Pat. No. 3,675,041. This type of system is expensive in that two complete systems are required. Copending application Ser. No. 079,072 referenced above discloses an improved system.